All engine faults/repairs/maintenance Oils recommended

General

Engine oil serves a few purposes including lubrication, cleaning, inhibiting corrosion, sealing and cooling. It also has to work fairly hard and in varying temperatures. This new page (in progress) shows the recommended oils for stock engines found in the T25 range and explains in simple terms, the numbers attached to oils. Alternative engines, Subarus, V12's whatever, fall outside the remit of this section and you should consult the manufacturers recommended lube chart for that particular engine, otherwise read on....

Firstly there is no 'right' or even 'perfect' oil but the basic recommendations below are certainly a good starting point. Engine oil is always being developed and not everyone here agrees, some preferring monograde (though why escapes me), some using cheap or expensive multigrade (multigrade being versatile and able to cope with a wide range of conditions), and even "Fantabidosa premium brand with added thingy" but one thing we do all agree on is no matter what oil you use - change it regularly. Regular oil changes and keeping the oil topped up matter far more than how much you actually spend on it. The VW engine isn't doing the high revolutions of most modern performance-orientated cars so will run quite happily on a budget brand (within reason) providing you change it regularly.

Many modern oils (read the label) are formulated to work in both petrol or diesel and some oil (even if not the ideal choice) is better than no oil at all. Listed below are VW recommendations followed by opinions and ideas put forward by various 80/90 club members over the years. Draw from it what you will. Additional links are provided for anyone who has time to kill and for reasons I have no wish to know, want to explore the world of 'oil' in more depth.

Numbers - What Does 15W40 Mean?

Firstly, monograde (which is what it is - one grade) can thin at higher temperatures and generally, does not offer anywhere near the protection of most modern multigrade oils. Even some of the cheapest multigrade is at least comparable with that recommended by VW in 1980-1990 and certainly before that. There are purists, particularly amongst bug owners who will use nothing else but I would much prefer to rely on an oil that can perform reliably throughout the year. Clearly there is a marked difference in temperature between starting an engine on a cold winters morning and an hour later hammering down the MI.

This difference in operating temperatures of engines, spawned the development of multigrade oils which perform well from cold and up to relatively high temperatures. Basically, multigrade engine oil numbers denote the cold and hot viscosity either side of the 'W' so 15W40 oil would perform like a 15 rated oil from cold and like a 40 when hot.

Following from that, a 10W40 would perform like a 10 rated oil from cold but some owners maintain that 10 is too thin for the VW engine and more likely to work its way past pistons and burnt although in exceedingly low temperatures more familiar to Eskimos, a low rating of 10 would be advantageous if you need to be up and about to trap seals. You get the picture.

Petrols

The specified oil is SAE 15W/40 for petrol engines - multigrade. Increasingly modern oils seem to come in wider ranges but this is a fairly common spec and readily available.

You can find good quality oil that meets and more often than not, exceeds VW T25 spec from some supermarket outlets these days and often, petrol forecourts have limited offers on engine oil. GSF, which has branches over almost all of the UK stock the 'Carlube' brand. As has been pointed out by other 80/90 members, cheap oils can be absolutely fine but they are not premium fandango brands disguised in a budget container. By the same token, it does not follow that spending £40 on a can of oil is going to be far superior in a T25 than the can you saw priced at £10 either. It would be wise to steer clear of containers that provide very little information, but certainly don't rule out an oil simply because it is cheap or assume that the more it costs, the longer your engine will last or the faster it will go. Read the label, and if it seems reasonably good, go by your instincts.

The concensus on 80/90 is that good old fashioned mineral oil is the best choice although some do use semi-synthetic. Mineral oils are, as the name implies, based on oil extracted from beneath our feet, and refined. Synthetic oil is manufactured from various chemicals, although by and large, most of the ingredients do in fact derive from mineral based oil. The other type is semi-synthetic - a mix of the two.

Good links

http://www.carbibles.com/engineoil_bible.html

Oil filters and recommendations